Digisette DUO-ARIA 64 MB E-Cassette Multi-Format Digital Audio Player 64 MB built-in memory--expandable to 128 MB using MultiMediaCards (MMCs) Use in virtually all audio cassette players; doubles as a stand-alone digital audio player Includes DC car power adapter/battery charger Plays content from Audible.com--including audiobooks, newspapers, magazines, and radio shows Upgradable firmware supports WMA, digital rights management, and new audio codecs